This invention generally relates to antenna systems and is particularly concerned with the provision of a receiving antenna constructed so as to exhibit inherent filtering action to thereby shape the frequency response curve thereof.
Antenna systems of virtually any form generally exhibit characteristic frequency response curves due to the interaction of the impedances of the antenna itself, the detector therefor, and the associated transmission line coupled thereto. In many varieties of such antenna systems wherein the detector is not directly coupled to the antenna, the frequency response curve of the antenna system can be shaped to exhibit desired characteristics through the utilization of a lumped-parameter filter. However, in some antenna systems such as dipoles or other linear antennas, or loop antennas, the detector which typically constitutes a diode is so directly coupled to the antenna elements as to render impractical the utilization of a lumped-parameter filter to correct and shape the frequency response curve.